Stay-bolt for boilers.



E. l. DDDS.

STAY BOLT FOR BOWERS.

APPLICATION FILED NOV` 30', 1914.

1,1 88,9 l 3. l Patented June 27, 1916.

"rl-IB COLUMBIA Puumwri WASHINGTON. D. c.

naar omen.

IETHAN I. DODDS, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR 'IO FLANNERY BOLTCOMPANY, OF PITTSBURGH, PENNSYLVANIA.

STAY-BOLT FOR BOILERS.

Specification of Letters Patent.

Patented June 27, 191

To all whom t may concern:

Be it known that I, Eri-IAN I. DoDDs, a citizen of the United States,and a resident of Pittsburgh, in the county of Allegheny and State ofPennsylvania, have invented certain new and useful Improvements inStay-Bolts for Boilers; and I do hereby declare the following to be afull, clear, and exact description of the invention, such as will enableothers skilled in the art to which it appertains to make and use thesame.

My invention relates to an improvement in stay bolts for boilers, theobject being to provide a bolt the shank of which will be yielding orflexible so as to accommodate itself to the unequal movements of the twosheets to which it is secured, without impairing its efficiency towithstand longitudinal stresses to which it may be subjected whenapplying it to the sheets, or when the boiler is in use.

Ti-th this object in View my invention consists inthe details ofconstruction as will be more fully explained and pointed out in theclaims.

In the accompanying drawings, Figure 1 is a view of a bolt blankembodying my invention; Figs. 2, 3 and 4 are views in transverse sectionof the same; Fig. 5 is a view of the blank with its shank twisted. andFigs. 6 to 19 inclusive are views of modifications.

In the manufacture of the bolt, a bar of stay bolt metal, preferablycylindrical, is subjected to an upsetting heat and is swaged betweendies or other tools to produce the reduced shank 1 and the enlargedheads 2 and 3. During the operation of swaging, or before or after thesame, the shank l of the bolt is slotted at opposite sides as shown at 4in dotted lines in Fig. 1. These slots are located diametricallyopposite each other as shown in Figs. 1 to 4 inclusive, each of theslots being deepest adjacent one head and gradually and uniformlydecreases in depth until it merges with the surface of the shankadjacent the other head, leaving a thin connecting web 5 intermediatethe bases or floors of the slots throughout the entire lengths of thelatter, and in no instance does either slot pass transversely throughthe shank. At each end of the shank, the web connecting the walls of theslots is at' the surface of the shank as shown in Figs. 2 and 4 but atintermediate points, where the slots overlap, the web separates theslots as shown in Fig. 3. After the blank has been shaped and slotted,the shank is twisted about 180o to carry the slots spirally around theshank as shown in Fig. 5.

In the construction shown in Figs. G to l0 inclusive I have simplyduplicated the slots, that is to say, I have slotted the opposite facestwice, instead of once as in the previous construction, the slots on oneside being` in the plane of the slots on the opposite sic e.

In Figs. 11 to 14 inclusive, I have shown the shank slotted as at 6, atone side from head 2 to approximately the center of the shank, and onits opposite side from head 3 to approximately the center as at 7, thebases of both slots being closed by the surface webs 8, and the twoslots 6 and 7 separated at the center of the shank by the transverse web9. lith this construction the two ends of the shank are made flexible soas to give under torsion or twisting strains, while the center of theshank is maintained in its original rigid condition.

Figs. 15 to 18 inclusive show the slots of Fig. 11 duplicated so as toincrease the flexibility of the shank at its ends, and Fig. 19 shows thesame twisted as in Fig. 5.

Slotting the bolt shank longitudinally as described1 does not materiallyaffect its capacity to withstand strains exerted longitudinally thereon,nor the torsional or twisting strains to which it may be subjected inapplying it to the sheets, but renders it sufliciently flexiblelaterally so that it may and will accommodate itself to the turning ortwisting movement to which it is subjected by the unequal expansion andcontraction of the inner and outer sheets of a boiler.

The slots above referred to are not formed by the removal of any metal,but simply by cutting or piercing it so that the capacity of the shankfor endwise stresses is not weakened.

Having fully described my invention what I claim as new and desire tosecure by LettersPatent, is

1. As a new article of manufacture, a stay bolt the shank of which isprovided with oppositely disposed slots each extending part way throughthe shank, the slot on one side of the shank being separated from theslot at the other side by a thin web integral with the shank.

2.' As a new article of manufacture, a stay bolt the shank of which isprovided with oppositely disposed slots, each slot being)` deepestadjacent one head of the bolts and merging with the surface adjacent theother head, the shallow end of each slot boing,` over the deepest end ofthe other slot.

3. As a new article of manufacture a stay bolt having oppositelydisposed slots each extending approximately the length of the shank, andeach extending nearly through the shank adjacent one head and'mergingCopies of this patent may be obtained for've cents each, by addressingthe `into the surface of the shank near the other ETHAN I. nonne.

lVtnesses Y WVM. CHARLES IBINGHAM,` EDWIN SPENCER RYGE.

' washington, n. c."

"Commissioner of Patents,

